1. Technical Field
The present disclosure relates to a heat storage apparatus, a method for storing heat, and a method for producing a heat storage apparatus.
2. Description of the Related Art
Hitherto, heat storage materials that store cold heat using latent heat have been known. Techniques for suppressing supercooling have also been reported.
Japanese Unexamined Patent Application Publication No. 54-102297 describes a heat storage apparatus including a heat storage material and a crystallization aid. As the heat storage material, a first clathrate compound of water, such as ethyl chloride hydrate, having a dodecahedral structure as a basic crystal structure is used. The crystallization aid promotes the crystallization of the heat storage material.
As the crystallization aid, a second clathrate compound of water, such as a hydrate of a tetrabutylammonium salt, having a dodecahedral structure as a basic crystal structure is used, the second clathrate compound of water being different from the first clathrate compound of water. The heat storage apparatus is provided with a porous partition to prevent the mixing of the heat storage material and the crystallization aid.
Japanese Patent No. 3324392 describes a heat storage material containing tetrabutylammonium nitrate hydrate serving as a main heat storage agent and a hydrate of a tetraalkylammonium salt which has a melting point of 20° C. or higher and which serves as a supercooling preventive agent. The supercooling preventive agent suppresses the supercooling of the main heat storage agent. To prevent the mixing of the main heat storage agent and the supercooling preventive agent, for example, a porous material is impregnated with the supercooling preventive agent. Furthermore, the mixing of the main heat storage agent and the supercooling preventive agent is prevented over a long period of time by covering a surface of the porous material with an organic coating and forming a small hole in the coating.
Japanese Unexamined Patent Application Publication No. 1-153785 describes a cold storage agent containing a guest agent, such as CFC R11, and a host agent, such as water, in which a clathrate is formed when the cold storage agent is cooled. The cold storage agent contains a metal element, such as Fe, in group II of the periodic table as a supercooling preventive agent.